Improvement in gas-and-air heating ovens



GEORGE F. WILSON.

I Patented June 18., 1872.

improvement in Gas and Air Heating Ovens.v "No. 128,004

STATES PATENT O EIoE.

IMPROVEMENT IN GAS-AND-AIRHEATING OVENS.

Specification forming part of Letters Patent No. 128,004, dated June 18,1872.

To whom it mayconce'rn:

Be it known that I, GEORGE F. WILSON, of Providence, in the county ofProvidence and .State of Rhode Island, have invented certain new'anduseful improvements in Gas-and- Air Heating Oven, to be'used inconnection with the gas-furnaces, in the process of manufacture ofsteel, for which Letters Patent of the United States were issued to me,on the 26th day of March, 1872, and numbered 125,- 107 and I herebydeclare the following to a full, clear, and exact description of thesame:

The use of gas-and-air heating ovens is desirable when the waste heatfrom gas-furnaces is to be used for heating boilers, &c.; or, as in thecase of the process for making steel, referred to, the heating, orpartial heating, of the converting-furnaces is effected in connectionwith them. In such cases the Siemens egenerating Gas-Furnaces can not beused, as all the waste heat from the gas-furnaces will necessarily berequired for the heating of the regenerators.

The principle of construction of my gas-andair heating oven is asfollows: The gas and air entering the oven by separate channels, passthrough heated fire-clay retorts, so connected that there are twoseparate continuous channels, one for the gas and one for the air, allthrough the oven. The retorts may be heated by means of grate-fires, or,when desirable, gas-fires. In the latter case, the gas and air for thefires could not be previously heated, but would produce heat enough forthe desired end. The gas and air can be made to pass through the heatedchannels of the oven by means of a back pressure, or the draught of achimney, or both. The extra pressure need be only very slight in anycase. That of the gas might be produced by means of an ordinarygas-holder, and that of the air by means of a fan-blower of lowpressure, like those sometimes employed to supply blast to the largechannels under the closed ash-pits of paddling and reheating furnaces.One desirable form for such a gas-and-air heating oven is represented inthe accompanying drawing.

Its principal advantages consist in the sim-' plicity of constructionand the ease with which leakages can be discovered, and consequentrepairs to the retorts made. The drawing does not represent the latter;but the outer wall of the oven, in front of and behind each retort, (ineach case an area of one square foot,) is to be only four and one-halfinches thick. Thus any retort can easily be inspected or removed aftermerely removing partly or wholly the thin wall in front of or behind it.Another advantage consists in the reversibility of the currents of airand of gas. These features recommend this form of furnace or oven veryhighly. The two uppermost tiers of retorts are designed for heating theair, and the two lowermost the gas. In each case the body to be heatedenters the oven at, and first passes through, the upper of its two tiersof retorts to the opposite side of the oven, when it passes down to andthrough the other tier. back again to the same side of the oven at whichit entered first, whence it passes hot into the channel of ingress tothe gas-furnace on that same side.

In the accompanying drawing, Figure 1 is a transverse vertical sectionon lineL M in Fig. 3. Fig. 2 is a longitudinal vertical section on lineI K, Fig. 4. Figs. 3, 4, 5, and 6 are horizontal sections on lines A B,E F, G D, and G H, respectively, of 'an oven constructed in accordancewith my said invention.

Figs. 3 and 4. show how the gas and air can be made to enter either endof the oven, according as it is necessary or desirable, to work thesuperincumbent gas-furnace in one direc tion or the other. Of course,when admitting the gas and air into the oven at one end, it is necessaryto close the corresponding channels of ingress at the other end, as wellas the connecting-channels between the oven and the exit-flues at theother end. By a proper management of the dampers at the dues leadingfrom the oven into the chamber above, which connects. with the chimney,(not'represented,) a sufficiently even temperature of the retortsthroughout the oven can be attained, although there will be a slightdifference between the temperatures of the several tiers, correspondingto their proximity to the grate-fires which is, in fact, the reason whythe gas and air are made to flow from one tier of retorts to and throughthat below it, instead of the reverse,

so that the last tier passed through may be the hottest, and the gas andair entering the gas-furnace may have a maximum attainable temperature.The partitions between the tiers of retorts should be made entirely oftiles, overlapping each other and carefully cemented together, to insurea minimum leakage in the joints. The vertical partitions need be onlysimple fire-brick work. The tiles are required for their supportingpower. If firebrick work were employed in their stead it would have toconsist of arches, (arch for tile,) which would increase the expense,and, from the multiplicity of joints, increase thetenden- H cy toleakage.

The horizontal tiles I prefer to make six inches thick; the holes forthe admission of retorts, one foot square; and the retorts four feetlong, with exterior diameter ten inches; interior diameter, six inches.The mode of closing the ingress of gas or air when required, and thearrangement of dampers for the regulation of the temperature of theoven, and for reversing, are not represented in the drawin g, as theseare wellknown to persons skilled in the art.

This gasand-air heating oven, in connection with a gasfurnace, could beused with advantage in cases where great heat is required, but the wasteflame from the gas-furnace would have a tendency to clog theregenerators, as in the case of certain smelting-furnaces, wherevolatile substances are sublimated. For example, in the smelting ofsilver-ores, Sie- Inens gas-regenerating furnaces have been applied withgreat advantage, (as indicated by an increase of one hundred per cent.in the production,) as long as the flues and passages of theregenerators were not clogged by sublimation from the flames of thegas-furnace; but, after a two-weeks campaign, it has invariably beennecessary to take apart the regenerators and clean them. This entailedso much expense as to lead to the abandonment of the whole plan. In sucha case, my oven, heated by grate-fires, could be employed with greatadvantage; while the waste-heat from the smelting-furnace could be usedin heating the boilers where all sublimated material could easily andinexpensively be removed.

The dimensions, relations, number of retorts, &c, as represented in theaccompanying drawing, may be varied without departure from my invention,according to the purpose for which the gas-furnace is to be employed,and according to the required temperature.

Having thus described my said invention, and the manner in which thesame may be carried into effect, what I claim, and desire to secure byLetters Patent, is-

The herein-described air-and-gas heating oven or furnace, provided withseparate series of two or more horizontal layers of tubes or retorts forpassage of the air and gas, respectively, the air and gas being causedto pass in a tortuous path through the successive tubes or retort-s ofthe upper layer of their respective series, and thence down in a likepath through the lower layer, in combination with fines for introducingand conducting off the air and gas into and from the retorts, soarranged that the air and gas may be caused to pass through the furnacein either direction at pleasure.

In testimony whereof I have signed my name to this specification beforetwo subscrib- WM. A. MUNRoE, GUsTAvE MAeNrrzKY.

